Electrical switch



Oct. 23, 1962 J. ELLIOT ELECTRICAL SWITCH 2 Sheets-Sheet 1 Filed June 26, 1958 INVENTOR. Lou/s J. ELLIOTT BY M i Oct. 23, 1962 L. J. ELLIOT ELECTRICAL SWITCH Filed June 26, 1958 2 Sheets-Sheet 2 @27 27 27 l IT 4 INVENTOR. Lpu/s J. ELLIOTT M} l W 5:

United States Patent Office 3,050,284 Patented Oct. 23, 1962 3,060,284 ELECTRICAL SWITUH Louis J. Elliot, Encinitas, Calif., assignor to Kinetics Corporation, Solana Beach, Calif., a corporation of California Filed June 26, 1958, Ser. No. 744,836 6 Claims. (Cl. 20016) The present invention relates to an electrical switch, and more particularly relates to an electrical switch wherein a pair of contacts are operated by linearly or axially moving one of the contacts with respect to the other of said contacts.

In certain applications, such as guided missiles and aircraft, it is extremely important to employ reliable components, and certain components have given particular difficulty in this regard because of the strenuous conditions under which they must operate. Extreme vibration, shock, and high acceleration and deceleration are characteristic of missile and aircraft operation, and frequently even components specifically designed to withstand such rough usage have not been satisfactory. Components having movable operating elements have been a particular problem, and electrical switches are of prime concern for that reason.

Accordingly, the present invention provides a relatively simple, rugged, and comparatively light weight switch which is adapted to withstand extreme vibration, shock, and other hard usage. The switch includes the usual mating contacts, or plurality thereof as desired, and provides for a novel means for aligning and operating such contacts. Thus, there are provided support means for aligning the contacts with each other, and means for axially or linearly urging one of said contacts toward and away from the other. Preferably, one of the contacts is stationary with respect to the switch assembly proper, and a carriage or the like is provided to carry the other contact. The carriage is caused to move in a linear or axial path by drive means engaged therewith to thereby effect switch contact. The switch elements are preferably made relatively large in transverse cross-section to thereby not only aiford low resistance characteristics and rugged performance, but also to permit the contacts to be employed as a guide for the carriage. That is, where a plurality of switch contacts are present, the making and breaking of such contacts may be so arranged that a pair of mating contacts are always in slidable engagement. By this means the engaged contacts act as ways along which the carriage may be supported and guided. However, as will be seen, the carriage in the present embodiment is primarily guided and supported by the drive means.

The switch of the present invention lends itself to switch sequencing operations by providing male contact elements of varying length so that they make and break in accordance with a predetermined sequence. Further, the length of the male contact elements may also be arranged so that there is a make in one set of contacts before there is a break in another set of contacts in the same circuit whereby undesirable flashing or arcing between the contacts may be prevented. The number of switch contacts which may be employed in the present switch have no practical limitation because of the possibility of miniaturization if necessary. As will be seen, the switch is already of relatively small size for its capacity, and multipole operations will be described.

Other objects and features of the present invention will be readily apparent to those skilled in the art from the following specification and appended drawings wherein is illustrated a preferred form of the invention, and in which:

FIGURE 1 is a front elevational view, in cross-section,

external circuitry to switch 11.

of the switch of the present invention, taken along II of FIGURE 4;

FIGURE 2 is a rear elevational view of the switch;

FIGURE 3 is a left end elevational view of the switch;

FIGURE 4 is a right end elevational view of the switch;

FIGURE 5 is a cross-sectional view taken along V-V of FIGURE 2, and

FIGURE 6 is a detail view of a coaxial form of switch contacts.

Referring to the drawings and more particularly to FIGURES 1 through 5, there is illustrated a multipole switch 11 according to the present invention, switch 11 being particularly adapted for aircraft and missile applications. Of course, it will be apparent that many other applications for switch 11 will suggest themselves to those skilled in the art, and the embodiments illustrated are therefore merely exemplary and not exhaustive.

Switch 11 comprises, generally, a plurality of male switch contacts 12, a plurality of female contacts 13 for mating with contacts 12, support means 14 for aligning the contacts for engagement with each other, and means 15 for shifting certain of said contacts linearly or axially with respect to the others of said contacts to effect engagement and disengagement thereof.

Support means 14 comprises a pair of vertically disposed support plates 16 and 17 which are made of a suitable electrical insulating material such as phenolic laminate or the like. Plates 16 and 17 are supported in spaced relationship, as illustrated, and are firmly anchored or secured in this position by a body of plastic material 18 which is poured about the lower edges of plates 16 and 17 and within a peripherally flanged tray, 19. Plastic material 18 may be any of the well-known potting plastics so commonly used in the electronics industry, as for example, the epoxy plastics which are capable of setting or polymerizing at room temperature and which have good electrical insulating characterictics.

Plates 16 and 17 are also rigidly secured in their spaced relationships by a plurality of heavy terminal straps 21 through 26, as best illustrated in FIGURES 3 and 4. As will be described in greater detail hereinafter, these terminal straps are connected to the plurality of female contacts, which are in turn carried by plates 16 and 17, and the lower ends of the terminal straps are anchored in the plastic material 18 and are each connected to a separate terminal 27. Since the terminal straps are fairly large in transverse cross-section, in the present embodiment being approximately x /2 inches, the desired structural rigidity is provided to plates 16 and 17. The terminal straps are preferably made of silverplated copper which, together with their generous cross-sectional size, provides an electrical path of low resistance.

Terminals 27 each comprise a vertical shaft or stud 28 having an integral, disc-like head or button upper portion 29 which is encased in the plastic material 18 and to which the lower end of one of the terminal straps 'is securely soldered. The studs 28 are disposed through suitable openings provided in tray 19 and are insulated therefrom by a pair of fiber insulating washers 31 which are carried by stud 28 in position adjacent to the upper surface and lower surfaces, respectively, of tray 19, whereby an insulated electrical path is provided between the terminal straps and the studs 28. In addition, the usual assembly 32 of nuts, washers, and lock washers is mounted upon each of studs 28 to provide means for securing the terminal leads (not shown) from Inasmuch as such circuitry is not important to the present invention, no description thereof will be made.

Other means may of course be used to anchor plates 16 and 17 in the position illustrated, but it has been found that the plastic material 18 affords an easy and convenient method for insuring that plates 16 and 17 are maintained in the desired position, and also materal 18 provides a moisture-proof insulating means for the terminals 27 and their associated terminal straps.

To further insure structural rigidity of plates 16 and 17, there are provided a plurality of tie rods arranged horizontally with their ends abutting the inner faces of plates 16 and 17, and secured thereto by a plurality of machine screws 34 which are carried in suitable countersunk openings in plates 16 and 17 and threaded into suitable threaded bores provided in the ends of tie rods 33. Tie rods 33 are of equal length and preferably a pair are provided at the front and rear edges of plates 16 and 17. Tie rods 33 are also maintained in a precision relationship to plates 16 and 17, as will be detailed hereinafter, by the placement of a fillet 35 of plastic material, similar to plastic material 18, at each of the ends of tie rods 33 where they abut against the inner faces of plates 16 and 17.

Thus it will be seen that support means 14 comprises a very rigid structure in which the various components are arranged in a precision relationship whereby a desirable accuracy of alignment characterizes the engagement and disengagement of contacts 12 and 13.

A movable plate, platform or carriage 36 made of suitable electrical insulating material, such as the phenolic material of plates 16 and 17, is mounted between plates 16 and 17 and is axially or linearly movable between plates 16 and 17. Carriage 36 is provided with a plurality of transverse openings 37 therethrough through which tie rods 33 are disposed, the size of openings 37 being made sufficiently greater than the size of tie rods 33 whereby carriage 36 is permitted to move axially along the length of tie rods 33 without coming into contact therewith.

A worm gear 33 is horizontally disposed between plates 16 and 17, and is rotatable within a pair of bearings 39 which are securely mounted in suitable openings provided in plates 16 and 17. Worm gear 38, together with a traveling nut element 41 which is threadably mounted upon worm gear 38 for movement therealong upon rtation of gear 38, forms a portion of the means for shifting male contacts 12. Worm gear 38 acts as a form of track along which carriage 36 is movable with the traveling element 41. As best seen in FIGURE 5, carriage 36 is secured to a flanged portion 42 of traveling element 41 by a plurality of machine screws 43 disposed through suitable openings in carriage 36 and threaded within threaded openings provided in flanged portion 42. The right end of worm gear 38, as viewed in FIGURE 2, is keyed to a gear 44, and this gear 44 is rotated by drive means to be hereinafter described. As will be apparent, rotation of worm gear 38 serves to axially or linearly move carriage '36 between plates 16 and 17.

Means for shifting certain of the electrical contacts to effect engagement and disengagement thereof includes a drive means or electric motor 45 which is rigidly secured as by bolts or the like (not shown), to support plate 16. A large cut out portion is provided in carriage 36 to permit carriage 36 to move between plates 16 and 17 without interference with motor 45, the size of the cut out portion being slightly larger than the transverse cross-sectional area of motor 45.

Motor 45, FIGURE 2, carries at its right end a gear 46 in engagement with gear 44, and the left end of the shaft carrying gear '46 carries a friction disc 47 which is engageable with, but normally spaced from, a mating friction disc 48 of a solenoid brake 49 which is rigidly secured to support plate 17 by a suitable machine screw 51. Discs 47 and 48 act as a clutch or friction brake which substantially instantaneously stops rotation of motor 45 upon energization of solenoid brake 49. Upon energization of brake 49 through a pair of suitable leads 52, disc 48 is urged outwardly into frictional contact with 4 disc 47 to effect the described braking of motor 45. Thus it will be seen that when current is applied to motor 45 through a pair of leads 53, gear 46 will effect rotation of gear 48 and consequent rotation of worm gear 38.

Female contacts 13, which in the present embodiment are carried by support plates 16 and 17, include a cylindrical base portion which is suitably fitted within appropriate openings provided in plates 16 and 17. Each of the base portions 54 is provided with a threaded bore which is adapted to threadably accept a machine screw 55 which is disposed through the adjacent or associated terminal strap for securing the terminal strap to the contact 13. This secures contact 13 in position and also provides an electrical path between contact 13 and the associated terminal strap. Screws 55 are preferably soldered to the terminal straps to insure minimum electrical resistance.

inwardly of base portion 54, contacts 13 each includes a collar portion which abuts against the inner face of plate 16, or plate 17 as the case may be. From this point the contact 13 tapers inwardly as illustrated. The tapered portion of each contact '13 is hollow to accommodate a male contact 12, and is slotted whereby the interior of the tapered portion may be made slightly smaller in cross-section than the cross-section of male contact 12 whereby male contact '12 will effect a biasing outward of the slotted portion of female contact 13 to thus secure satisfactory peripheral contact between the contacts 12 and 13. Contacts 12 and 13 are preferably made of silverplated copper for low electrical resistance. Male contacts 12 are each made cylindrical in configuration for mating with an adjacent female contact '13, and are horizontally mounted in suitable openings in carriage 36. Any suitable means may be provided for rigidly mounting contacts 12 to carriage 36, but in the present invention this rigidity is afforded by the heavy circuit or conductor straps 56 which are each fitted within a suit able slot in the faces of carriage 36, and soldered at its ends to a pair of male contacts 12. With this construction, as carriage 36 is moved between plates 16 and 17, male contacts 12 will engage and be slidably introduced within the hollow interior of the sleeve-like tapered portions of each female contact :13. It will be apparent that although the present embodiment teaches the carriage of the male contact by carriage 36, with the female contacts being stationary, the arrangement could be reversed so that carriage '36 would carry the female contacts 13 and the male contacts be arranged in stationary relation.

As illustrated in FIGURE 1, the male contacts 12 may be made of various lengths so that any sequence of contacts may be predetermined by making the length of the contacts 12 correspond with the sequence desired. Thus, for example, the upper contact 12 of FIGURE 1 will effect engagement with the upper contact 13 prior to the erigagement between the lower contacts 12 and 13. In addition, it is noted that engagement between contact 12 and the left contact 13 of the upper opposed contacts 13 will be made before complete disengagement between contact 12 and the right contact 13 of said pair. Thus a make before break is provided for the circuit to which the pair of upper contacts 13 are connected.

In operation, carriage 36 may be moved to a precise point, and stopped at that point by energization of solenoid brake 49, whereby a precision sequencing of contact engagement and disengagement may be had.

To be sure that contacts '12 and 13 are in perfect alignment, the assembly of switch 11 is important. Thus, plates 16 and 17, tie rods 33, carriage 36, and contacts 13 are mounted in position, and carriage '36 is urged to the right, as viewed in FIGURE 1, until contacts 12 mate with contacts 13. At this point plastic material 18 is poured into position, similar plastic material is provided at the ends of rods 33 in the form of fillets 35, and similar plastic material 57 is provided around each of the contacts 13 about their base portion 54 and about the base of the tapered portions of contacts 13 adjacent the inner face of plate 17. When the plastic has set up or polymerized, carriage 36 is then moved to the left into engagement with the left-most contacts 13 and similar plastic material is placed about those contacts 13 and permitted to set up. In this fashion precision alignment between the contacts is afforded.

In FIGURE 6 there is illustrated an alternative form of contacts 12 and 13 whereby instead of effecting connection and disconnection between one circuit, the contacts are made co-axial, as in contacts 58 and 59. Each of the pair of female contacts '58 is similar to the female contact 13 previously described except that the base portion thereof is provided with an internal bore within which is fitted an insulating sleeve 61 which in turn is provided with an internal bore for accepting a central, axially disposed probe or pin conductor 62. Male contact '59 is provided with an internal bore for accepting an insulating sleeve 63 which in turn includes a cylindrical or tubular electrical conducting sleeve 64, made of copper or the like. As will be apparent, tube 64 is adapted to receive pins 62 to effect electrical connection between the leads 65, and the outer conducting sleeve of contact 59 is adapted to be received within the hollow interior of female contacts 58 to effect connection between the electrical circuit of a pair of leads 66. In this manner each set of mating contacts 58 and 59 are adapted to handle the circuits of the two sets of leads 65 and 66. This arrangement is particularly useful in applications where compactness and small size is important.

While certain preferred embodiments of the invention have been specifically disclosed, it is understood that the invention is not limited thereto as many variations will be readily apparent to those skilled in the art and the invention is to be given its broadest possible interpretation within the terms of the following claims:

I claim:

1. An electrical switch comprising, in combination, a first set of longitudinally extending male contacts; a second set of longitudinally extending female contacts, said female contacts each including a recess whose walls are adapted to closely mate with the peripheryof one of said male contacts and slidably engage the same linearly such that said recess generally envelopes said one of said male contacts longitudinally and all transverse movement of said one male contact increases the contact pressure on one side of said male contact substantially in proportion to the decrease in contact pressure on the opposite side of said male contact; support means for aligning said contacts for engagement with one another; and means for shifting the contacts of one of said sets of contacts linearly with respect to the corresponding contacts of the other of said sets of contacts, the lengths of certain of the contacts of one of said first and said second sets being different than the lengths of the others of the contacts of said one of said first and second sets whereby engagement between the contacts of said first and said second sets is sequential.

2. An electric switch comprising, in combination, a first set of longitudinally extending male contacts; a second set of longitudinally extending female contacts, said female contacts and slidably engage the same linearly such that to closely mate with the periphery of one of said male contacts and slidably engage the same linearally such that said recess generally envelopes said one of said male contacts longitudinally and all transverse movement of said one male contact increases the contact pressure on one side of said male contact substantially in proportion to the decrease in contact pressure on the opposite side of said male contact; support means for the contacts of one of said sets of contacts, said one of said sets of contacts being rigidly carried by said support means whereby a substantially rigid construction is provided; a carriage for the contacts of the other of said sets of contacts and movable toward and away from said support means, said contacts of the other of said sets of contacts being rigidly carried by said carriage whereby a substantially rigid construction is provided, and said support means and said carriage being disposed for maintaining the contacts in correspond-v ing linear alignment with one another; and means for moving said carriage, the lengths of certain of the contacts of said first set being different than the lengths of the others of the contacts of said first set whereby engagement between the contacts of said first and said second sets is sequential.

3. An electric switch comprising, in combination, a first set of longitudinally extending male contacts; a second set of longitudinally extending female contacts, said female contacts each including a recess whose walls are adapted to closely mate with the periphery of one of said male contacts whereby any transverse movement of said one male contact increases the contact pressure on one side of said male contact substantially in proportion to the decrease in contact pressure on the opposite side of said male contact, and wherein at least one of the contacts of said second set is a female contact which is provided with a hollow receptacle portion forming a receptacle sleeve, and also is provided with an axially extending pin conductor centrally located within said receptacle sleeve, and at least one of the contacts of said first set is a male contact which includes an outer sleeve, an intermediate insulating sleeve within said outer sleeve, and an inner sleeve within said intermediate sleeve, said outer sleeve being adapted to fit within said receptacle sleeve, said inner sleeve being adapted to receive said pin conductor; support means for aligning said contacts for engagement with one another; and means for shifting the contacts of one of said sets of contacts linearly with respect to the contacts of the other of said sets of contacts, the lengths of certain of the contacts of one of said first and said second sets being different than the lengths of the others of the contacts of said one of said first and second sets whereby engagement between the contacts of said first and said second sets is sequential.

4. An electric switch comprising, in combination, a first set of longitudinally extending male contacts; a second set of longitudinally extending female contacts, said female contacts each including a recess whose walls are adapted to closely mate with the periphery of one of said male contacts whereby any transverse movement of said one male contact increases the contact pressure on one side of said male contact substantially in proportion to the decrease in contact pressure on the opposite side of said male contact; support means for the contacts of one of said sets of contacts, said one of said sets of contacts being rigidly carried by said support means whereby a substantially rigid construction is provided; a carriage for the contacts of the other of said sets of contacts and movable toward and away from said support means, said contacts of the other of said sets of contacts being rigidly carried by said carriage whereby a substantially rigid construction is provided, said support means and said carriage being disposed for maintaining the contacts in alignment with one another; and means for moving said carriage including a worm gear rotatably mounted between said support means and said carriage and geared to said carriage, and an electrical motor mounted to said support means and coupled to said worm gear for axially moving said carriage at a predetermined rate, the lengths of certain of the contacts of said first set being different than the lengths of the others of the contacts of said first set whereby engagement between the contacts of said first and said second sets is sequential.

5. An electric switch comprising, in combination, a first set of longitudinally extending male contacts; a second set of longitudinally extending female contacts, said female contacts each including a recess whose walls are adapted to closely mate with the periphery of one of said male contacts whereby any transverse movement of said one male contact increases the contact pressure on one side of said male contact substantially in proportion to the decrease in contact pressure on the opposite side of said male contact; support means for the contacts of one of said sets of contacts, said one of said sets of contacts being rigidly carried by said support means whereby a substantially rigid construction is provided; a carriage for the contacts of the other of said sets of contacts and movable toward and away from said support means, said contacts of the other of said sets of contacts being rigidly carried by said carriage whereby a substantially rigid construction is provided, said support means and said carriage being disposed for maintaining the contacts in alignment with one another, and wherein the contacts of said one of said sets of contacts are anchored to said support means in alignment with the contacts of said other of said sets of contacts by the provision of fillets of potting mate rial at the juncture between the contacts of said one of said sets of contacts and said support means; and means for moving said carriage, the lengths of certain of the contacts of said first set being difierent than the lengths of the others of the contacts of said first set whereby engagement between the contacts of said first and said second sets is sequential.

6. An electric switch comprising, in combination, a first set of longitudinally extending male contacts; a second set of longitudinally extending female contacts, said female contacts each including a recess whose walls are adapted to closely mate with the periphery of one of said male contacts whereby any transverse movement of said one male contact increases the contact pressure on one side of said male contact substantially in proportion to the decrease in contact pressure on the opposite side of said male contact; support means for the contacts of one of said sets of contacts, said one of said sets of contacts being rigid-1y carried by said support means whereby a substantially rigid construction is provided; a carriage for the contacts of the other of said sets of contacts and movable toward and away from said support means, said contacts of the other of said sets of contacts being rigidly carried by said carriage whereby a substantially rigid construction is provided, said support means and said carriage being disposed for maintaining the contacts in align ment with each other; and means for moving said carriage including a braking surface, a worm gear rotatably mounted between said support means and said carriage and geared to said carriage for axially moving said carriage at a predetermined rate to effect sequential engagement and disengagement of said male contacts and said female contacts, and brake means having a braking surface and operable to urge its braking surface into engagement with the braking surface of said drive means to render said drive means inoperable, the lengths of certain of the contacts of said first set being different than the lengths of the others of the contacts of said first set whereby engagement between the contacts of said first and second set is sequential.

References Cited in the file of this patent UNITED STATES PATENTS 258,149 Stern May 16, 1882 477,374 Klein June 21, 1892 777,631 Henderson Dec. 13, 1904 810,389 Bijur Jan. 23, 1906 1,366,466 Kermode Jan. 25, 1921 1,843,804 Christie Feb. 2, 1932 1,852,868 Whitney et al. Apr. 5, 1932 2,175,897 Johnson Oct. 10, 1939 2,276,740 Saito Mar. 17, 1942 2,429,401 Davis Oct. 21, 1947 2,473,565 Bird June 21, 1949 2,480,140 (ester Aug. 30, 1949 2,501,274 Hamilton Mar. 21, 1950 2,637,787 Price May 5, 1953 2,643,294 Shaw lune 23, 1953 FOREIGN PATENTS 692,035 France July 28, 1930 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent Noe 3,060,284 October 23 1962 Louis Elliot It is hereby certified that error appears in the above numberedpatent requiring correction and that the said Letters Patent should read as corrected below.

Column 5 line 63 after "contacts" strike out "and slidably engage the same linearly such that's. and insert instead each including a recess whose walls are adapted column 8, line B for "each other" read one another Signed and sealed this 27th day of August 1963,

(SEAL) Attest:

ERNEST w. SWIDER DAVID D Attesting Officer Commissioner of Patents UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent N00 $060,284 October 23, 1962 Louis Jo Elliot It is hereby certified that error appears in the above numbereipatent requiring correction and that the said Letters Patent should read as corrected below.

Column 5, line 63 after "contacts" strike out "and slidahly engage the same linearly such that! and insert instead each including a recess whose walls are adapted column 8, line 5, for "each other" read one another Signed and sealed this 27th day of August 19630 (SEAL) Attest:

ERNEST w. SWIDER DAVID LADD Attesting Officer I Commissioner of Patents 

